It's getting harder to tell the difference among the plethora of models in QNAP's catalog. The latest tweak to its "SMB & Corporate NAS" line is the addition of USB 3.0 ports in its "Pro II" models.

Like the Pro + NASes before them, the Pro II's are powered by Intel D525 Atom CPUs. But to earn the "Pro II" moniker, they also get a pair of USB 3.0 ports. The Pro II's include the six-bay TS-659 Pro II, four-bay TS-459 Pro II and the object of this review, the TS-559 Pro II. (Note that the older TS-439 Pro II+ and TS-239 Pro II+ have neither D525's or USB 3.0 ports. Confused?)

The 559 Pro II looks just like QNAP's other five bay NASes. The only way you know what you've got is to look at the serial # label on the bottom or boot it up and look at the model number in the front panel LCD display.

But a glance at the rear panel reveals one of the two USB 3.0 ports. The other is on the front panel, sporting USB 3.0's telltale light blue color. Also in view below are the four USB 2.0 ports, dual Gigabit Ethernet ports supporting aggregation, failover and load balance modes and two eSATA ports.

Plug a monitor and USB mouse / keyboard into the handy VGA and USB ports and you'll have direct console access, which you can also get via SSH.

I removed the cover to get a peek inside, and ran right into an empty So-DIMM connector that allows you to add 1 or 2 GB more of DDR3 RAM with QNAP's blessings. As is QNAP's custom, the board is mounted component-side in. I tried to get the board out, but couldn't get the drive bay connector completely free without more disassembly than I wanted.

By the partial disassembly I was able to do, I was able to spy two Intel WG82574L Gigabit Ethernet Controllers an ITE IT8718F Super I/O, and NEC D720200F1 USB 3.0 controller. I poked around a bit trying various commands to try to determine the D525's companion chip, which of course was covered by a heatsink, but came up empty. The photo below provides a partial view of the board component side.

QNAP installed five Samsung Spinpoint F3 HD103SJ 1 TB drives for testing. These produced a 51 W power draw with the drives spun up and 28 W with them spun down. Fan noise was generally low, except for the typical high fan rate at the start of boot time. But an annoying buzz from the enclosure kept me pushing and whacking at the cabinet during testing.

The NAS auto-upgraded to 3.4.3 Build 0520T
firmware before I started testing. The V3 OS continues to be tweaked and I noticed that ElephantDrive has been added as a cloud backup option in addition to Amazon S3.

There is also a MyCloudNAS Service menu that is QNAP's way of trying to make it easy for you to have access to your NAS from the Internet. QNAP provides a dynamic DNS service with three different domain names. But you have to map ports for the services you need. The gallery shows the wizard and manual configuration steps

Here's the latest list of QPKG add-ons available.

Setup for the ElephantDrive cloud backup option

Setting up the MyCloudNAS remote access option can be done via a wizard

You have your choice of three domains for your subdomain

You then select the services you want exposed to the Internet for remote access. Note that there is no Step 3 in the Wizard

If your router doesn't have UPnP, or it's not enabled, or it's behind another router (like mine), you get this message

The manual configuration screen

Here is where you manually select the services you want published

The Auto Router Configuration uses the same UPnP mechanism. So if the wizard fails, then this will too.